Fabrics obtained by weaving warps and wefts have conventionally been used widely as an industrial fabric. They are, for example, used in various fields including papermaking wires, conveyor belts and filter cloths and are required to have fabric properties suited for the intended use or using environment. Of such fabrics, a papermaking wire used in a papermaking step for removing water from raw materials by making use of the network of the fabric must satisfy a severe demand. There is therefore a demand for the development of fabrics which do not transfer a wire mark of the fabric and therefore have excellent surface property, have enough rigidity and therefore are usable desirably even under severe environments, and are capable of maintaining conditions necessary for making good paper for a prolonged period of time. In addition, fiber supporting property, improvement in a papermaking yield, good water drainage property, wear resistance, dimensional stability and running stability are demanded. In recent years, owing to the speed-up of a papermaking machine, requirements for papermaking wires become severe further.
Since most of the demands for industrial fabrics and solutions thereof can be understood if papermaking fabrics on which the most severe demand is imposed among industrial fabrics will be described, the present invention will hereinafter be described by using the papermaking fabric as a representative example.
In the paper making machine, an increase in paper making speed inevitably raises dehydration speed so that dehydration power must be reinforced. Examples of the fabric with good dehydration property include two-layer fabric having a dehydration hole penetrating from the upper surface side toward the lower surface side of the fabric. Particularly, a two-layer fabric using a warp binding yarn which is woven with an upper surface side weft and a lower surface side weft to constitute an upper surface side surface design and a lower surface side surface design is developed with a view to satisfying the surface property, fiber supporting property and dehydration property which a papermaking fabric is required to have. A two-layer fabric using a warp binding yarn is described in Japanese Patent Laid-Open Publication No. 2004-36052. The fabric disclosed in the above-described invention is a two-layer fabric using, as some warps, a warp yarn functioning as a binding yarn to weave therewith an upper surface side layer and a lower surface side layer. Two warp binding yarns forming a pair complement each other to form the upper surface side surface design and the lower surface side surface so that the fabric has excellent surface property and binding strength. A lower surface side design of the fabric in Examples 1 to 3 of Japanese Patent Laid-Open Publication No. 2004-36052 is however a ribbed design in which two lower surface side warps are arranged in parallel with the same design and a lower surface side weft is designed to form a short crimp corresponding to only two warps on the lower surface side surface so that the fabric has poor wear resistance.